Continuous casting apparatus having a two part separable mold

ABSTRACT

A mold assembly for a continuous casting mold, which has an open ended mold cavity therethrough, is in two parts that are separable at a plane extending axially through the cavity. The parts are held together, under pressure, by springs, or hydraulic or pneumatic means, and they are separated by toggle levers, which are operable to overcome the pressure normally holding the parts together. Guide rolls adjacent the exit end of the mold cavity, for guiding a strand out of the mold, hold the emerging strand in fixed axial relation to the center line of the mold cavity. The mold assembly is constructed and arranged for both parts of the mold to move back from opposite sides of a strand in the mold, when the mold parts are separated at the end of a casting run, and thereby assure complete release of the strand from the mold.

United. States Patent [72] Inventors Eric'I.Vogel [54] CONTINUOUS CASTING APPARATUS HAVING A TWO PART SEPARABLE MOLD 9 Claims, 7 Drawing Figs. [52] US. Cl 164/273,

. 164/283. 164/82 [5 1] Int. Cl 822d 11/00 [50] Field ofSearch l64/82, 83. I37, 273, 280. 283. 339, 341-343. 282

[56] References Cited UNITED STATES PATENTS 3,364,980 l/ l 968 Loewenstein 164/28 1 2,195,809 4/1940 Betterton et al. 164/82 2,289,928 7/1942 Parker 164/342 2,698,978 l/ 1955 Welblund 164/83 3,262,158 7/1966 Von Reimer et al l64/342X 3,416,222 12/ 1968 Pearson l 64/ 82X FOREIGN PATENTS 829,523 4/ I938 France l64/343 Primary Examiner-J. Spencer Overholser Assistant Examiner-R. Spencer Annear Attorney-Sandoe, Neill, Schottler & Wikstrom ABSTRACT: A mold assembly for a continuous casting mold,

which has an open ended mold cavity therethrough, is in two parts'that are separable at a plane extending axially through the cavity. The parts are held together, under pressure, by springs, or hydraulic or pneumatic means, and they are separated by toggle levers, which are operable to overcome the pressure normally holding the parts together. Guide rolls adjacent the exit end of the mold cavity, for guiding a strand out of the mold, hold the emerging strand in fixed axial relation to the center line of the mold cavity. The mold assembly is constructed and arranged for both parts of the mold to move back from opposite sides of a strand in the mold, when the mold parts are separated at the end of a casting run, and

thereby assure complete release of the strand from the mold.

PATENIEIl FEB 2 I97| sum 1 BF 4 BMH INVENTORS C T. V

ATTORNEYS PAT'ENTEU FEB 215m SHEET 2 OF 4 TOF mm R AT TORNEYS PATENTED FEB 2 IQYI SHEET 3 BF 4.

INVENTORS WWW ATTORNEYS CONTINUOUS CASTING APPARATUS HAVING A TWO PART SEPARABLE MOLD The present invention relates to a mold assembly for continuous casting metal. such as steel, and particularly to a mold that is separable in two parts for releasing the tail end of a cast strand at the end of a casting run.

In continuous casting molten metal is poured into one end of an open-end mold cavity through the mold. The mold is cooled and solidifies the periphery of the metal in the cavity to form a cast strand which is drawn out of the other end. Additional metal is poured into the cavity to replace the metal drawn out as a continuously cast strand. At the end of a casting run, the flow of molten metal into the mold is stopped and the tail end of the cast strand is left in the mold long enough for its upper end and sides to solidify. This is referred to in the art as capping the strand. When the tail end is solidified, or at least sufficiently solidified to contain any metal which may still be molten in the core of strand, it is withdrawn from the mold. Of course, as the tail end of the strand solidifies, it shrinks, and if it is round, rectangular. or some other crosssectional shape which is not indented or deeply concave, the shrinkage loosens it in the cavity so that it is easily drawn out. If, however, the cross-sectional shape of the strand is deeply indented-as in the case of channel, rail, I, or dog bone (bulbous ends with a slim section between) shapes, for example-the inner walls of the indentation or indentations shrink against the corresponding wall surfaces of the mold cavity and lock the tail end of the casting in the mold so that it is difiicult or impossible to withdraw. This problem is customarily avoided by limiting the depth and the steepness and sharpness of the indentations of cross-sectional shapes that are cast with continuous casting apparatus and by tapering the molds. The molds can only be tapered to a small extent, however, without rendering them inoperable. Consequently, when it is desired to use continuous casting methods to produce channels, rails, I beams or other shapes having deep and/or sharply defined indentations, the initial cast shape must be modified to reduce the depths and sharpness of the indentations so that the casting must subsequently be forged or rolled to a considerable extent to produce the desired shape. This increases the cost and reduces the advantagesnamely, increased production rates, reduced cost of equipment and greater economy of operation- -of continuous casting as compared with alternate forming methods consisting of casting ingots that are first hammered and rolled into blooms and billets and subsequently rolled or forged into the final shapes desired.

It is an object of the present invention to provide a continuous casting mold assembly wherein the mold is separable in two parts from around the tail end of the casting whereby the mold cavity may be formed for casting strands having crosssectional shapes with relatively deep, sharply defined indentations without the tail end of the casting sticking in the mold when it has been capped at the end of a casting run. This makes it possible to cast strands having more nearly the final indented shape desired than possible with conventional continuous casting mold assemblies: consequently, the number of forging or rolling operations to give the casting the desired final shape, and hence the cost of producing the finished article, is greatly reduced.

Molds separable in parts for releasing a casting are known in the casting art in general, but up to the present there has not been a practical separable mold for use in continuous casting. It is believed this is due to the particular problems involved in providing an effective and economic separable mold for continuous casting. For example, a mold which is separable in two parts must be adapted for the parts to be held firmly together in a manner to withstand separation by the considerable ferrostatic pressure of metal in the mold cavity, and yet be readily separable to release the casting. Moreover, in order to ensure complete release, both separable parts of the mold would have to be drawn back from the casting while the casting is held stationary in one axial position; otherwise, if only one part moves, the casting might still stick to the other. Also, continuous casting molds are customarily cooled continuously by circulating a liquid coolant-customarily water-through passages in the mold walls or through a jacket around the liner. defining the mold cavity, and the connections to the source of coolant and the passages or jacket structure would have to be adapted for the separation and movement of both parts.

In accordance with the present invention, the mold assembly includes a mold in two parts separable at a plane extending axially through the mold cavity. The parts are firmly held together under pressure-by springs, or by pneumatic or hydraulic means-and are separated by an array of toggle levers adapted to overcome the pressure under which the parts are normally held together. The two parts and the toggle levers are mounted for both parts to be moved back from a casting in the mold as the parts are separated. The mold parts are mounted to be supported in correct axial alignment as they move, and they are each provided with cooling means, which move with them as they separate.

The mold assembly of this invention therefore makes it possible to use continuous casting molds having deeper and sharper indentations in their cross-sectional configurations, than heretofore practicable. This permits the continuous casting of rails, I beam shapes, channel shapes, and other deeply indented shapes and forms, and reduces considerably the number of subsequent forging or rolling operations necessary to produce the finished shapes and dimensions desired, thereby reducing production expense and the capital cost of the equipment needed to produce them.

Further objects, advantages and features of this invention will be apparent from the following description of an illustrative embodiment depicted in the accompanying drawings wherein:

FIG. 1 is a schematic diagram of a vertical section through a continuous casting mold and guide apron extending from the mold illustrating the general structure and arrangement of a mold assembly in accordance with this invention;

FIG. 2 is a top plan view, partly in section, of a mold assembly embodying the invention and showing the mold in closed position;

FIG. 3 is an enlarged end elevation, partly broken away and partly in section, of the right-hand end of the mold assembly shown in FIG. 2;

FIG. 4 is a side elevation, partly broken away and partly in section, looking at the side of the mold assembly which is lowermost in FIG. 2;

FIG. 5 is a section along the lines 5-5 of FIG. 4;

FIG. 6 is a partial, enlarged top plan view, partly broken away in section, of the upper right-hand portion of the mold shown in FIG. 2; and

FIG. 7 is a partial view of the right-hand end of the mold assembly as seen in FIG. 3, but showing the mold in open positlOIt.

Referring to the drawings, FIG. 1 illustrates schematically a continuous'casting mold assembly of this invention in use.

In continuous casting molten metal, such as steel, is poured from a supply indicated by the outlet 10 of a tundish, into the upper end of an open-ended mold cavity 11 of a mold 12. The walls of the mold cavity 11 are cooled by suitable means, such as by circulating water through channels in the mold or through a jacket around the mold, to solidify the periphery of the metal in the mold to form a strand 13 which is drawn from the bottom end of the mold cavity.

At the start of casting, the lower end of the mold cavity is stoppered with a plug (not shown) which is customarily provided with a mushroom-shaped projection or undercut portion around which the metal in the mold solidifies to fuze the plug to the lead end of the strand 13 being formed in the mold. When sufficient molten metal is backed up in the mold by the plug for a strand to form, the plug is withdrawn to start the strand down, out of the lower end of the mold cavity. Guide rolls I4, mounted to be at opposite sides of the emerging strand l3, withdraw, support and guide the strand into a support and guide apron 15. which conducts the strand away from the mold. In the drawing the apron is indicated as being a curved chute; in practice the apron 15 may be provided by a sequence of support rollers, support panels or other suitable means. The strand 13 may be conducted straight down from the mold. but in many conventional continuous casting machines the strand is conducted along a curved path, as shown, to lead it into a horizontal path 'which is more convenient for subsequent forming or cutting operations.

When the strand emerges from the mold the core is still molten and furthercooling is applied. first to prevent the molten core from remelting 'th'e solidified periphery or skin of the strand and then to further solidify the strand. For this purpose cooling means, such as water sprays, indicated at 1,6, are applied to the strand at spaced intervals therealong.

The casting operation is continued by pouring molten metal into the top of the mold cavity to replace metal comprising the strand emerging from the bottom of the mold cavity. To end a casting run the flow of molten metal to' the mold is discontinued and the strand is capped by halting the withdrawal of the strand untilthe tail end of the strand in the mold solidifies completely. If the cross-sectional shape of the strand formed by the shape of the mold cavity is round, rectangular or some other shape which does not have indented portions, the shrinkage of the solidifying metal loosens the strand in the mold; but if the shape has deep indentations or undercut portions-as with the cross-sectional shapes of rails, I-beams and channels, for examplethe shrinkage of the metal locks the strand into the mold cavity. This locking-in of a capped strand is avoided in a mold assembly in accordance with the present invention wherein the mold 12 is in two halves 12a and 12b which separate along a vertical plane axially through the mold cavity 11. During casting the mold halves 12a and 12b are held together by pressure means-such as springs, indicated schematically at 17 in FIG. I, or by pneumatic or hydraulic power cylinders-which are adapted to hold the halves firmly together under sufficient pressure to resist separation by the ferrostatic pressure of molten steel in the mold. At the end of a casting run, when the tail end of the strand has solidified suffieiently in the mold, the mold halves 12a and 12b are separated to release the strand by the toggle mechanism which is adapted to overcome the pressure normally applied by the pressure means and move the mold halves apart. Illustrative structure and the mode of operation of the toggle mechanism are described in detail below.

In the mold assembly shown in FIGS. 27 the two halves 12a and 12b of the mold 12 are supported in a rectangular frame 19 formed by two opposite vertical end panels 20 attached to two opposite vertical side panels 21 by bolts 22. The frame 19 in turn is supported in a central opening 23 of a mold table 24, which, as indicated in FIGS. 2 and 3, is a rectangular structure, having a generally flat upper surface, and which is a fixed part of a conventional continuous casting machine. As best seen in FIGS. 2 and 4, the frame 19 is supported in the mold table openings 23 by lugs 25 attached to, and projecting out from, the respective end panels 20 of the frame 19 to project over the surface of the mold table at opposite ends of the opening 23. The outward ends of the lugs 25 are provided with holes 26 to receive upwardly projecting pins 27, which are carried in laterally adjustable supports 28 on the mold table 24, so that with the pins 27 received in the holes 26, the lugs are supported by the supports 28; the pins 27 serve to locate the lateral position of the frame 19, and the mold 12 carried therein, relative to the tundish outlet 10 above the mold and the guide rolls 14 below.

Referring to FIGS. 2 and 3, the means for pressing the mold halves 12a and 12b together are provided by a plurality of opposed concave disc springs 30 carried on rods 31 attached to pistons 32 which are slidable in cylinders 33. The cylinders 33 are attached to, and open through, the side panels 21 of frame 19 respectively at opposite sides of the mold 12, with the face of the piston 32 in each cylinder bearing against the outside of one or the other of the mold halves 12a and 12b. In the assembly illustrated in the drawings there are four cylinderseach carrying disc springs 30-for each mold half. As seen in FIG. 3, the outer end of each cylinder is closed by a threaded plug 34 that has a central bore 35 for the outer end of the rod 31 to slide through; the disc springs on the rod are compressed between the piston 32 and the plug 34 to press the head of the piston against the side of the adjacent mold half under spring pressure, which may be adjusted by screwing the plug 34 inward or outward in the cylinder.

Pressure means, such'as pneumatic or hydraulic power, could be used instead of springs 30 as means for pressing the mold halves 12a and 12b together. In operation the toggle mechanism, which separates the mold halves for opening the mold, operates by overcoming the pressure'normally applied by the pressure means for pressing the mold halves together. If pneumatic power is used, an extra reservoir of air may be connected in a conventional manner to assure the degree of further compressibility of air necessary for the toggle mechanism to overcome the pressure of air normally applied to hold the mold halves together. If hydraulic power is used, conventional pressure relief valves would be connected to release the pressure at a predetermined value of overpressure applied by the toggle mechanism for separating the mold halves.

As seen in FIG. 3, toggle mechanism for separating the mold halves 12a and 12b is provided at each end of the mold. It is the same at each end and includes a pair of toggle levers 37 and 38 respectively at the upper and lower portions of the mold. Each toggle lever has respectively two lever arms 37a and 37b and 38a and 38b pivotally connected end to end by knee pivots 39 and 40 to form knee joints. The outer, end of the lever arms of each toggle lever 37 and 38 are pivotally connected respectively to the mold halves 12a and 12b by pivot pins 37c and 37d and 380 and 38d, which are attached in the respective lever arms and pivotably received in appropriate holes in blocks 41a and 42a and 41b and 42b that are attached on the upper and lower outside comer portions of the mold halves 12a and 12b by bolts 43.

As shown in FIG. 3, the blocks 41a and 42a on mold half 12a and blocks 41b and 42b respectively on mold half 12b are spaced apart to define a horizontal slide path between them for lugs 44a and 44b connected to, and extending" inward from, the respective opposite side panels 21 of frame 19. The lugs 44a and 44b thus support and guide the mold halves in proper mating alignment when the mold is opened (FIG. 7) and closed (FIG. 3), the direction of movement being indicated by arrows in FIG. 7.

Referring now to FIGS. 2, 3, the respective lever arms 37a and 37b and 38a and 38b are connected and arranged so that they meet at an angle at their knee pivots 39 and 40, when the mold is in closed position. For opening the mold, the central parts of both toggle levers 37 and 38, at their knee pivots 39 and 40, are pulled in the same direction (down) so that the angle formed by arms of each toggle lever flattens out (FIG. 7). For this purpose both toggle levers 37 and 38 are moved in unison by a link 45 having'its ends connected respectively to the knee pivots 39 and 40.

The toggle levers 37 and 38 and link 45 at each endof the mold 12 are arranged in a space between the end of the mold and the adjacent end plate 20 of the frame 19, and the link 45 has an outwardly projecting vertical rib 45a which slides in a vertical groove 20a in the end plate 20. Thus, the link 45 is confined to move in afixed vertical path so that its movement, which opens (and closes) the mold by moving the centers of the toggle levers, moves the knee pivots 39 and 40 in a fixed vertical path so that the toggle lever arms move both mold halves 12a and 12b out.(and back) from the center line 0-0 of the mold.

When the shape of the mold cavity 1 1 is such that the crosssectional shape of the casting is sharply and/or deeply indented, the mold 12 is constructed so that the two mold halves 12a and 12b separate at a vertical plane which extends through the mold cavity at right angles to the plane of symmctry of the cross-sectional configuration of the mold cavity. or to any other appropriate plane, so that the mold halves are free to be drawn apart without being locked in behind undercut portions of the configuration of the mold cavity.

The link 45 is moved in its vertical path for opening and closing the mold by a lever 46. which is pivotally mounted on frame 19 by a pivot pin 47 which is through the central portion of the lever 46 and fixed between the adjacent end panel 20 and the lug 44b that is attached to the left-hand side panel 21. as viewed in FIGS. 3 and 7. The ends of lever 46 are forked at 460 and 46b, and at one end of the lever 46 forked end 46a embraces flattened side portions of a pin 48 which is pivotally mounted on the link 45 to extend outward therefrom. The forked end 46a embraces the pin 48 loosely to enable the pin to slide back and forth within the fork for relative vertical movement of link 45 and pivotal movement of the lever 46. and to provide clearance to allow for heat expansion.

At the other end of lever 46 forked end 46b slidably embraces a block 49 that is pivotally mounted on a nut 50 which is threaded on a central screw-threaded portion 51 of a shaft 52. There is a similar link 45 and shaft 52 at each opposite end of the mold 12 at one side. Each shaft 52 is rotatably mounted to be parallel with the vertical paths of movement of the respective links 45 and their bottom ends rotatably supported in a suitable bearing assembly 53 attached to the outside of side panel 21 The upper portions of the shafts 52 are supported through journals 54, which are mounted in a shelf 55b of a pair of outward extending shelves 55a and 55b attached to the side panels 2] of frame 19. Each shaft 52 has a gear 56 attached on its upper end to mesh with a worm gear 57 which is mounted on a drive shaft 58. As seen in FIG. 2, there is a worm gear 57 for each of the two gears 56, and the drive shaft 58 is adapted to be rotated by a suitable reversible motor (not shown) through a conventional drive connection (not shown). When the drive shaft 58 is rotated, it causes the cooperating gears 57 and 56 to rotate screw-threaded shafts 52 which causes the nuts 50 threaded thereon to move up or down-depending on the direction of rotation of the drive shaft 58- and carry the blocks 50 up or down to pivot the levers 46 and thereby open or close the mold 12. The movement of lever 46 is limited by adjustable stop blocks 36.

As shown in FIGS. 2 and 6, when the mold halves 12a and 12b move toward each other to close the mold. they are guided into and maintained in exact mating relation by riblike keys 60 projecting from the face of one of the mold halves (12a in the drawings) to be received in cooperating keyways 61 in the face of the other mold half.

In continuous casting, the mold is customarily cooled by means which is operative to continually carry heat away from the walls of the mold cavity to enable the casting to be carried out on a continuous basis. This cooling is ordinarily accomplished by circulating a coolant, such as water, through the walls of the mold or through a jacket around the mold. Means for cooling the separable mold halves 12a and 12b of a mold in accordance with the present invention comprise generally conduits for conducting water from a suitable supply source (not shown) to and away from passages through each of the mold halves 12a and 1212.

Referring to FIGS. 2 and 3, an inlet pipe 63 and an outlet chamber 64 are mounted on each of the shelves 55a and 55b at opposite sides of the frame 19 and are connected at one end to conventional supply and drain conduits by readily separable connections, illustrated by the connection 65, which is shown in section at the right-hand end of FIG. 3 connecting an outlet 64 to a drain 66, which is attached to the mold table 24. This connection 65 is formed by a downwardly projecting annular flange 67, attached on the underside of the shelf 55a around, and spaced from the edge of, an opening 68 through the shelf into the outlet chamber 64, and a pair of parallel annular flanges 69 projecting up from an adjusting ferrule 70 on drain 66. The flanges 69 are spaced apart and arranged to receive the downwardly projecting flange 67 between them with the end of the flange 67 resting on an annular soft rubber gasket 71 which is between the flanges 69 for making a leak tight seal. Thus. the connections 65 between the inlet pipes 63 and outlet chambers 64 on the shelves 55a and 55b and supply and drain conduits which are attached to the mold table 24 are completed. without having to attach and tighten any screw or clamp-type connections, when the frame 19. carrying the mold l2 and associated elements of the mold assembly. is set down in place on the mold table 24.

The inlet pipes 63 and outlet chamber 64 at each side of the mold are connected (by feeder pipes. hoses and connections subsequently described-in detail) to a system of passages consisting of horizontal passages 72 and vertical passages 73, within the walls of the mold halves 12a and 12b. As illustrated in FIGSv 4 and 6, the horizontal passages 72 are drilled into the mold halves 12a and 12b from the outward sides, near the tops and bottoms of the mold halves, to intersect the upper and lower ends of vertical passages 73. which are shown as being partially filled by rods 74. The vertical passages 73 are formed by drilling up into the mold halves 12a and 12b from the bottoms to intersect the horizontal passages 72; the bottom open ends of the passages 73 are then plugged. Due to the length of the holes which must be drilled to form the vertical passages 73. drills for drilling holes the exact, relatively small, diameter desired are more apt to break than larger diameter drills. Therefore, the passages 73 are drilled to a larger diameter, which is less costly due to the reduced breakage of drills; than, before plugging the bottom ends of passages 73, rods 74 are inserted to reduce them to a size which will provide a desired volume and velocity of fluid flow. As illustrated in FIG. 4, each rod 74 has a flattened side 75, which provides a vertical fluid-flow passage along the length of each rod, and reduced annular portions 76 at its end portions that are at the portions of the passage 73 which are intersected by horizontal passages 72. These annular portions 76 thus provide connections between the horizontal passages 72 and the vertical passages formed by the flattened sides 75 or rods 74.

The outer ends of the horizontal passages 72 at the top and bottom portions, at two locations along the outward sides, of each of the mold halves, 12a and 12b, are connected respectively to the outlet chamber 64 and inlet pipe 63 by feeder pipes 77 at the top and by feeder pipes 78 at the bottom that are connected respectively into cuplike distributor elements 79 which are attached to the outer sides of the mold halves over the outer, open ends of the passages 72 by bolts 80. As shown in FIGS. 4 and 6, each distributor element 79 covers the open ends of a group of passages 72 and has a peripheral, inwardly directed flange 79a bearing against the side of the mold half to form a chamber 79b through which fluid flows between the passages 72 and the feeder pipe 77 (in FIG. 6) which is connected through the backwall of the distributor element.

As previously described, the mold halves 12a and 12b move apart and come together within the frame 19, and the inlet 'pipes 63 and outlet chambers 64 are fixed on the shelves 55a and 55b, which are attached to frame 19. The feeder pipes 77 and 78, connected between these relatively movable elements, must therefore be adapted to permit this movement without breaking connection. For this purpose the upper feeder pipes 77 each include an expansion joint 81, illustrated in FIG. 5, consisting of a short pipe 82, connected at one end into the distributor element 79 with its other end slidably received in a sleeve 83. A leaktight slidable connection between the pipe 82 and sleeve 83 is provided by packing rings 84 around the pipe 82 between a bushing 85 and the end of the sleeve 83 with a retaining ring 86 slidable on the sleeve 83 and encircling the bushing 85 and packing rings 84. The retaining ring 86 has a lip 86a engaging the exposed end of bushing 85, and a capscrew 87 through an annular raised portion of the sleeve 83 is threaded into the end of the retaining ring 86 for drawing the retaining ring, and bushing 85, toward the sleeve to compress the packing rings 84 against the pipe 82 for tightening the seal. A nipple 88 connects the outer end of the sleeve 83 to a coupling 89 that is threaded onto an elbow 90 which is connected into the outlet chambers 64. As seen in FIG. 2. at each V side of the mold two feeder pipes 77. with expansion joints 81 therein, are connected between one of the mold halves 12a and 12b and an outlet chamber 64.

Similar expansion joints 81 could also be utilized in the lower feeder pipes 78, but in the embodiment shown a similar function is provided by including a section of flexible pipe 91 (of rubber, plastic, woven material or other suitable material) between a pipe 92 from each of the distributor elements 79 and the respective inlet pipes 63 at each side of the mold. As indicated in FIG. 3, the flexible pipes 91 are suitably connected to the pipes 92 and to distributor elements 79 by hose clamps 93.

The mold 12 is cooled during casting by circulating water, or other suitable cooling fluid, through the walls of the mold halves 12a and 12b, from their bottom to their top portions, and then out to be dumped, or to be cooled and recirculated. ln the assembly illustrated, cooling fluid from a suitable source (not shown) is fed into the inlet pipes 63 at opposite sides of the mold l2 and flows down through the feeder pipes 78 to the distributor elements 79 on the lower portions of the mold halves 12a and 12b, from which it flows through the several groups of horizontal passages 72 in the lower portions of the mold halves into the lower ends of the vertical passages73. At the upper ends of the vertical passages, the groups of horizontal passages 72 in the upper portions of the mold halves 12a and 12b carry the fluid out into the adjacent distributor elements, which are on the upper portions of the mold halves, and from which the fluid is conducted by the feeder pipes 77 into the outlet chambers 64. Drains 66 then carry the fluid away from the mold to be dumped or recirculated.

It is to be understood that the embodiment of the invention shown in the drawings and described in detail above is illustrative only and that the structure and mode of operation may be varied without departing from the scope of the invention defined by the following claims.

We claim:

1. An apparatus for continuous casting of metal having a mold with a deeply indented open-ended cavity therethrough wherein molten metal poured in one end of the cavity is peripherally solidified in the mold and withdrawn as a cast strand from the other end, said mold comprising two parts separable at a plane extending axially through the cavity, pressure means for applying constant pressure to urge the two mold parts together firmly, mold part separation means for overcoming the pressure applied by the pressure means and drawing back the two mold parts for releasing the tail end of a cast strand from the mold at the end of a casting run and means for holding said strand axially stationary during mold separation.

2. The apparatus of claim 1 in which each of said parts is supported to move relatively toward and away from said plane, and said pressure means are arranged at the two opposite sides of the mold relative to said plane to enable each of the parts to be moved back from the plane against pressure applied by the pressure means.

3. The apparatus of claim 2 which includes in combination: guide and support means mounted in fixed position relative to said plane adjacent the end of the mold cavity, from which a cast strand emerges, for supporting said strand in fixed axial relation to said plane; and means for separating the two parts by moving each of them back from said plane.

4. The apparatus of claim 3 in which the release means comprises at least one toggle lever having two lever arms pivotally connected end to end'to form a knee joint, the outer ends of the lever arms being pivotally connected respectively to the two parts of the mold for its lever arms to be at an angle at the knee joint when the parts of the mold are together, said toggle lever being mounted for movement of the knee joint in a line at right angles to the direction in which the mold parts move apart for separating the parts by moveme'ritof the knee joint in one direction and then bringing them back together by movement in the opposite direction, and means for moving the knee joint in said directions.

5. The apparatus of claim 4 including means confining the knee joint in a path of movement in a straight line parallel to the direction of the axis of the mold cavity, and means supporting and guiding the two parts of the mold for movement in a plane at right angles to the direction of the axis of the mold cavity.

6. The apparatus of claim 5 including at least one of said toggle levers at two opposite ends of the mold.

7. The apparatus of claim 5 including a pair of said toggle levers connected to said parts at one end of the mold with their respective knee joints aligned for separating the parts by movement of the respective knee joints in the same direction, a link pivotally connected to each of the knee joints, a lever having one end pivotally connected to the link, said lever being pivotally mounted for moving the link and knee joints in successively opposite directions for separating the parts of the mold and bringing them together again.

8. The apparatus of claim 7 including means for pivoting said lever comprising a threaded shaft arranged at an angle to the lever and parallel to the plane of movement thereof, a block threaded on the shaft, said block being pivotally connected to the other end of the lever, and means for rotating the shaft for moving the block relatively along the shaft to thereby pivot the lever.

9. The apparatus of claim 7 including a second pair of said toggle levers, mounted on the opposite end of the mold, and having a link pivotally connected to each of the knee joints of said second pair, a lever for each pair of toggle levers, said levers each having one end pivotally connected respectively to one of said links and being pivotally mounted for moving the links and knee joints in successively opposite directions for separating the pans of the mold and bringing them together again, a threaded shaft for each lever, said threaded shafts being arranged respectively at an angle to the levers and parallel to the planes of movement thereof, said threaded shafts each having a block threaded thereon, with said blocks pivotally connected respectively to said levers, a rotatable drive shaft, and gear means operatively connecting the drive shaft and said threaded shafts for rotating the latter shafts when the drive shaft is rotated, thereby to move the blocks relatively along the threaded shafts to pivot the levers for separating the parts of the mold and then bringing them together. 

1. An apparatus for continuous casting of metal having a mold with a deeply indented open-ended cavity therethrough wherein molten metal poured in one end of the cavity is peripherally solidified in the mold and withdrawn as a cast strand from the other end, said mold comprising two parts separable at a plane extending axially through the cavity, pressure means for applying constant pressure to urge the two mold parts together firmly, mold part separation means for overcoming the pressure applied by the pressure means and drawing back the two mold parts for releasing the tail end of a cast strand from the mold at the end of a casting run and means for holding said strand axially stationary during mold separation.
 2. The apparatus of claim 1 in which each of said parts is supported to move relatively toward and away from said plane, and said pressure means are arranged at the two opposite sides of the mold relative to said plane to enable each of the parts to be moved back from the plane against pressure applied by the pressure means.
 3. The apparatus of claim 2 which includes in combination: guide and support means mounted in fixed position relative to said plane adjacent the end of the mold cavity, from which a cast strand emerges, for supporting said strand in fixed axial relation to said plane; and means for separating the two parts by moving each of them back from said plane.
 4. The apparatus of claim 3 in which the release means comprises at least one toggle lever having two lever arms pivotally connected end to end to form a knee joint, the outer ends of the lever arms being pivotally connected respectively to the two parts of the mold for its lever arms to be at an angle at the knee joint when the parts of the mold are together, said toggle lever being mounted for movement of the knee joint in a line at right angles to the direction in which the mold parts move apart for separating the parts by movement of the knee joint in one direction and then bringing them back together by movement in the opposite direction, and means for moving the knee joiNt in said directions.
 5. The apparatus of claim 4 including means confining the knee joint in a path of movement in a straight line parallel to the direction of the axis of the mold cavity, and means supporting and guiding the two parts of the mold for movement in a plane at right angles to the direction of the axis of the mold cavity.
 6. The apparatus of claim 5 including at least one of said toggle levers at two opposite ends of the mold.
 7. The apparatus of claim 5 including a pair of said toggle levers connected to said parts at one end of the mold with their respective knee joints aligned for separating the parts by movement of the respective knee joints in the same direction, a link pivotally connected to each of the knee joints, a lever having one end pivotally connected to the link, said lever being pivotally mounted for moving the link and knee joints in successively opposite directions for separating the parts of the mold and bringing them together again.
 8. The apparatus of claim 7 including means for pivoting said lever comprising a threaded shaft arranged at an angle to the lever and parallel to the plane of movement thereof, a block threaded on the shaft, said block being pivotally connected to the other end of the lever, and means for rotating the shaft for moving the block relatively along the shaft to thereby pivot the lever.
 9. The apparatus of claim 7 including a second pair of said toggle levers, mounted on the opposite end of the mold, and having a link pivotally connected to each of the knee joints of said second pair, a lever for each pair of toggle levers, said levers each having one end pivotally connected respectively to one of said links and being pivotally mounted for moving the links and knee joints in successively opposite directions for separating the parts of the mold and bringing them together again, a threaded shaft for each lever, said threaded shafts being arranged respectively at an angle to the levers and parallel to the planes of movement thereof, said threaded shafts each having a block threaded thereon, with said blocks pivotally connected respectively to said levers, a rotatable drive shaft, and gear means operatively connecting the drive shaft and said threaded shafts for rotating the latter shafts when the drive shaft is rotated, thereby to move the blocks relatively along the threaded shafts to pivot the levers for separating the parts of the mold and then bringing them together. 